Heating and cooling systems for buildings or other structures typically maintain temperature control in a structure by circulating a fluid within coiled tubes such that passing another fluid over the tubes effects a transfer of thermal energy between the two fluids. A primary component in such a system is a compressor which receives a relatively cool, low pressure gas and discharges a hot, high pressure gas. Compressors include positive displacement compressors such as screw compressors, reciprocating compressors and scroll compressors, as well as compressors such as centrifugal compressors. Typically, an electric motor is used to power the compressor, although gas turbines have been used in large capacity systems. Recent advancements have resulted in the utilization of a variable speed motor to power a compressor such as a centrifugal compressor for use in large capacity systems and take advantage of chiller unit efficiencies during partial loading, when operation at a speed lower than full design load speed is desirable.
Another means to power a compressor in a high capacity system is a steam turbine. Steam turbines have been used less frequently to power compressors within a chiller unit, partially due to the excessive field work required to install the system and the unavailability of pre-packaged units that completely integrate the operation of the steam turbine, steam condenser and the chiller unit.
What is needed is a cost-effective, efficient and easily implemented method or apparatus for powering the compressor of a chiller unit with a steam turbine.